Automatic Map Rotation and Scale

[DouglasBurn]

I've been working on an aerial survey application, and was able to get out for a test flight last week.  In order to help orient the observer to the real world, it seems like enabling automatic map rotation would be a good feature.  However, when ArcPad automatically pans to keep the aircraft location on screen, it occasionally changes the map scale (and it always zooms out).  I've been unable to find any documentation on this feature, so it's not clear how to control it.

Does anyone have any experience or insights on this?

Thanks in advance,

Doug

[CalCrawford]

same thing is happening to us, as well.  we're running a custom app written by an arcpad programmer, but not sure it has anything to do with the app.  when the app was removed from applets, we still had the phantom zoom issue.  we are running arcpad 8.0 on laptops with win xp, external gps, aerial photos in a custom projection (also could be the culprit) and 3 .shp files running as a floating map.

[EddieViljoen]

Hi Doug
What version of ArcPad are you using?

This used to be a problem in version 7.xx and I really hoped that this feature (According to ESRI) has been fixed in version 10.

We worked around it in version 7 as follows:

1. Created a button to "lock" the mapscale at the current value
Sub Lockmapscale
   Application.Userproperties("MapScale") = Application.Map.Scale
   Mustlockscale = True
End Sub

2. In the Arcpad.apx file call a sub each time a valid GPS pos is received
<SYSTEMOBJECTS>
   <GPS onopen="call DoSetMapRotationOn" onclose="DoSetMapRotationOff" onposition="Call ResetZoom"/>
</SYSTEMOBJECTS>

3.  Make sure the zoom level stays the same
Sub ResetZoom
  If Application.Map.Scale <> Application.Userproperties("MapScale")  and mustlockscale = true then
     Application.Map.Scale = Application.Userproperties("MapScale") 
End sub

This is not the most elegant sollution, but it works.

Eddie

[MaxRingler]

I can second that - when the map is rotated manually and then panned or rescaled, this  causes the map view to pan or rescale entirely erratically and not in  the desired way of the specific pan or rescale applied. Basically this  renders the rotation function entirely useless as it requires to  pan and zoom in again to the needed map section if this  happens.

Apperently this a known, 6-year old bug which still has not been adressed...